| S L Roofing Systems & Solutions Ltd | Construction | 2020 |
| S R Hesleden Limited | Other services | 2019 |
| S W Cowley & Co Ltd | Construction | 2019 |
| S W Hurst Welding Limited | Manufacturing | 2012 |
| S Waplington Limited | Other services | 2014 |
| S&L Renovations Ltd | Administrative & support | 2026 |
| S-Communications Ltd | Administrative & support | 2016 |
| S.A.K. Industrial Cleaning Limited | Administrative & support | 2007 |
| S.I.S Domestic Ltd | Construction | 2021 |
| S2 Builders Limited | Construction | 2013 |
| S2 Real Estate Limited | Real estate | 2024 |
| SA Empire Club Ltd | Professional & scientific | 2023 |
| Saber Homes Limited | Real estate | 2021 |
| SAD Onion | | 2005 |
| Safe-T-Solutions UK Ltd | Administrative & support | 2008 |
| Safer Infrastructure Limited | Professional & scientific | 2018 |
| Sagenta Limited | Health & social care | 2023 |
| Saltire Limited | Real estate | 1987 |
| Salzburger GmbH UK Limited | Other services | 2023 |
| SAM Barnard Web DEV Ltd | Other services | 2021 |
| Sandbeck Hospitality Limited | Other services | 2019 |
| Sandbeck Stud Ltd | Other services | 2017 |
| Sanderson Business Growth Limited | Administrative & support | 2025 |
| Santander Property Ltd | Real estate | 2020 |
| Santanida Limited | Health & social care | 2014 |
| SAP HV Solutions Limited | Administrative & support | 2013 |
| Sapore DI Fantasia Ltd | Extraterritorial | 2024 |
| Sarah Habgood Ltd | Transport & logistics | 2022 |
| Savvy Taxi Gainsborough Ltd | Transport & logistics | 2025 |
| SAVVYBUYS24 Limited | Wholesale & retail | 2025 |
| Saxon Fleet Limited | Wholesale & retail | 2025 |
| Saxon Property Law Limited | Professional & scientific | 2025 |
| SC Comps Ltd | Administrative & support | 2022 |
| SC Prod Limited | Arts & recreation | 2024 |
| Scarlett's (Lincs) Ltd | Other services | 2019 |
| Scotties Catering Limited | Hospitality | 2008 |
| Scrub-It Ltd | Other services | 2017 |
| SCS Property Development Limited | Real estate | 2006 |
| Scunthorpe Chiropody Clinic Ltd | Health & social care | 2013 |
| Scunthorpe Mini Kicks Limited | Arts & recreation | 2016 |
| SD Carpentry & Joinery Ltd | Construction | 2025 |
| SDB Roofing Specialists Ltd | Construction | 2018 |
| SDM Pest Ltd | Administrative & support | 2024 |
| Sea-Shaw Ltd | Administrative & support | 2022 |
| Seatox International Ltd | Construction | 2026 |
| Seatox Renewable Energy Ltd | Construction | 2025 |
| Seco Solutions (20-20) Limited | Professional & scientific | 2020 |
| Sedgeford Estates Ltd | Real estate | 2017 |
| Seistrain Ltd | Information & communication | 2020 |
| Selby Farms Limited | Agriculture & fishing | 1964 |
| Selfie Limited | Other services | 2014 |
| Selmaverse Productions Ltd | Arts & recreation | 2026 |
| Seraphim Projects Ltd | Professional & scientific | 2014 |
| Service Plus Install Ltd | Construction | 2020 |
| Seweezy Limited | Wholesale & retail | 2017 |
| Sewing Chest Limited | Wholesale & retail | 2015 |
| SF Luxury Travel Ltd | Administrative & support | 2018 |
| SG Support Service Ltd | Other services | 2023 |
| SH Properties Gainsborough Ltd | Real estate | 2026 |
| Shaker Surgery Limited | Health & social care | 2024 |
| Sharni K Hair Ltd | Other services | 2017 |
| Sharons Shed Ltd | Wholesale & retail | 2024 |
| Shaw Equine Ltd | Agriculture & fishing | 2023 |
| SHE Builds CRM Ltd | Information & communication | 2025 |
| Sheffield Accommodation Services Ltd | Real estate | 2019 |
| Shelftalker Limited | Information & communication | 2025 |
| Shell and Auger Services Limited | Construction | 1996 |
| Shen Clothing Ltd | Wholesale & retail | 2022 |
| Sherwood Park 1969 Limited | Extraterritorial | 2014 |
| Shovel & Pick Limited | Construction | 2024 |
| Sidney Property Limited | Real estate | 2024 |
| Sigma Construction Lincs Ltd | Construction | 2022 |
| Signature Events Decor Ltd | Hospitality | 2026 |
| Silvervault Limited | Real estate | 2022 |
| Simfreight Limited | Transport & logistics | 2009 |
| Simon Frank Carter Limited | Extraterritorial | 2025 |
| Simon Holmes (Holdings) Limited | Extraterritorial | 2003 |
| Simon Holmes Limited | Financial services | 1999 |
| Simon Properties Limited | Real estate | 1999 |
| Simpkins Kenny Limited | Construction | 1992 |
| Simplicityhub Ltd | Information & communication | 2026 |
| Simply Safe Car Seats Ltd | Wholesale & retail | 2023 |
| Sina Market Ltd | Wholesale & retail | 2025 |
| Sinclair-Fallon Ltd | Construction | 2021 |
| Sing IT Loud Ltd | Education | 2026 |
| SIS Drill (UK) Ltd | Construction | 2017 |
| SIX Fifty Limited | Wholesale & retail | 2012 |
| SJ LEE Contracting Ltd | Other services | 2023 |
| Sjpropertyandsurveying Limited | Real estate | 2024 |
| SJW Brand Limited | Wholesale & retail | 2024 |
| SK Compliance Limited | Other services | 2019 |
| SKA Online Ltd | Administrative & support | 2013 |
| Skillbard Limited | Information & communication | 2021 |
| Skin TAG & Lesion Health Clinic Ltd | Other services | 2026 |
| SKP Transport Services Ltd | Transport & logistics | 2025 |
| Sky Business Limited | Manufacturing | 2017 |
| Sky EYE Vision Limited | Professional & scientific | 2022 |
| Sleaford Grab Hire Ltd | Construction | 2025 |
| Sljd Industial Ltd | Construction | 2025 |
| SLR Electrical Ltd | Construction | 2024 |